def get_rounds(number):
    """

     :param number: int - current round number.
     :return: list - current round and the two that follow.
    """
    return range(number, number + 3)


def concatenate_rounds(rounds_1: list, rounds_2: list):
    """

    :param rounds_1: list - first rounds played.
    :param rounds_2: list - second set of rounds played.
    :return: list - all rounds played.
    """
    return rounds_1.extend(rounds_2)


def list_contains_round(rounds:list, number):
    """

    :param rounds: list - rounds played.
    :param number: int - round number.
    :return:  bool - was the round played?
    """
    return rounds.index(number) != -1


def card_average(hand: list):
    """

    :param hand: list - cards in hand.
    :return:  float - average value of the cards in the hand.
    """
    length = len(hand)
    if length == 0:
        return 0.0
    return sum(hand) / length



def approx_average_is_average(hand):
    """

    :param hand: list - cards in hand.
    :return: bool - is approximate average the same as true average?
    """

    pass


def average_even_is_average_odd(hand):
    """

    :param hand: list - cards in hand.
    :return: bool - are even and odd averages equal?
    """

    pass


def maybe_double_last(hand):
    """

    :param hand: list - cards in hand.
    :return: list - hand with Jacks (if present) value doubled.
    """

    pass
